#include <bits/stdc++.h>
using namespace std;

string f(string s1, string s2) {
	string nums = "0123456789abcdefghijklmnopqrstuvwxyz";
	int i = s1.size() - 1;
	int j = s2.size() - 1;
	int temp = 0;
	string sb;
	while (i >= 0 && j >= 0) {
		char c1 = s1[i];
		char c2 = s2[j];
		int index1 = nums.find(c1);
		int index2 = nums.find(c2);
		int sum = index1 + index2 + temp;
		if (sum >= 36) {
			temp = 1;
			sb += (nums[sum % 36]);
		} else {
			temp = 0;
			sb += (nums[sum]);
		}
		i--;
		j--;
	}

	while (i >= 0) {
		int sum = nums.find(s1[i]) + temp;
		if (sum >= 36) {
			temp = 1;
			sb += (nums[(sum % 36)]);
		} else {
			temp = 0;
			sb += (nums[sum]);
		}
		i--;
	}

	while (j >= 0) {
		int sum = nums.find(s2[j]) + temp;
		if (sum >= 36) {
			temp = 1;
			sb += (nums[sum % 36]);
		} else {
			temp = 0;
			sb += (nums[(sum)]);
		}
		j--;
	}
	if (temp != 0) {
		sb += '1';
	}
	reverse(sb.begin(), sb.end());
	return sb;
}

int mian() {
	string a, b, c;
	cin >> a >> b;
	c = f(a, b);
	cout << c << endl;
	return 0;
}

